Many cosmetics and personal care products employ various film forming agents to aid in spreading and adhering a formulation to a surface such as skin. The class of polymers known as organosiloxanes, including polydimethylsiloxane (PDMS or Dimethicone), have recently received considerable attention as film-formers in cosmetic products due to their excellent spreading properties and biological inertness. Examples of cosmetic formulations including organosiloxane film formers include, for example, U.S. Pat. No. 6,780,402 (L'Oreal), U.S. Pat. No. 5,318,775 (Mary Kay Cosmetics), U.S. Pat. No. 4,699,780 (Estee Lauder); and U.S. Pat. No. 4,578,266 (Revlon), the disclosures of which are hereby incorporated by reference. In the case of the foregoing patents, the organosiloxane polymers do not undergo cross-linking to form more robust films when applied to a surface and therefore are of limited durability, transfer resistance, and water-resistance.
Recently, in situ condensation cross-linking organsiloxane film formation has been described in U.S. Pat. No. 6,512,072, the contents of which is hereby incorporated by reference. The described film-forming compositions comprise 5 to 79.9 weight % of an alkylene trialkoxy terminated polysiloxane; 0.01 to 5 weight % of a catalyst; 20 to 94.99 to weight % of a volatile diluent, and, optionally, 0.01 to 5 weight % of an alkoxysilane and 0.1 to 25 weight % of a filler.
In addition to condensation cross-linking, it is known to form cross-linked silicones through the metal-catalyzed addition reaction between olefins and siloxanes having reactive Si—H functionalities. See generally, Speier, J. L. et al., J. Amer. Chem. Soc., 79, 974 (1957); Lewis, L. N.; Lewis N., J. Am. Chem. Soc. 108, 7228 (1986), the disclosures of which are hereby incorporated by reference. EP 0465744, which is hereby incorporated by reference, discloses in situ addition reaction cross-linking of a polysiloxane having alkylhydrogen siloxane units with a polysiloxane having unsaturated groups in the presence of a platinum or rhodium catalyst for forming a dressing capable of sustained release of therapeutic or diagnostic agents to the body. EP 0465744
Despite the advances in film forming methods and compositions, there remains a need in the art for in situ cross-linked organosiloxane film formers which provide long-lasting, comfortable, highly flexible, tack-free, and water-proof films.
It is therefore an object of the invention to provide compositions and methods for forming in situ cross-linked organosiloxane films.
It is further an object of the invention to provide cosmetic and personal care compositions comprising in situ cross-linked organosiloxane films.